{"title":"Tohatsu 2.5-6 HP 4-Stroke Outboard Marine Engine Parts","description":"\u003csection id=\"hero\" style=\"padding:16px 0;\"\u003e\n  \u003cp style=\"max-width:900px;\"\u003e\n    This page supports Tohatsu 2.5–6 HP 4‑Stroke outboard engines and helps you find compatible parts and service information. Below you’ll find maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse the main Tohatsu collection. Scroll to the bottom of this page to start browsing parts for this engine; on the collection page, use the “Filter \u0026amp; Sort” controls to narrow results by horsepower, year range, and part category.\n  \u003c\/p\u003e\n  \u003ca href=\"https:\/\/seasierra.com\/collections\/tohatsu-outboard-parts\" style=\"display:inline-block;padding:10px 14px;border-radius:6px;background:#0b6efd;color:#fff;text-decoration:none;\"\u003eBrowse All Tohatsu Parts\u003c\/a\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\" style=\"padding:16px 0;\"\u003e\n  \u003ch2\u003eHow to Identify Your 2.5–6 HP Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eLocate the nameplate\/serial plate on the transom clamp bracket or swivel bracket. It lists the model code and serial number.\u003c\/li\u003e\n    \u003cli\u003eModel codes for 4‑stroke Tohatsu portables often begin with “MFS” (e.g., MFS2.5, MFS3.5, MFS4\/5\/6). Suffix letters typically indicate shaft length (S = 15 in, L = 20 in) and other options.\u003c\/li\u003e\n    \u003cli\u003e2.5\/3.5 HP models are compact, manual‑start units with an integral fuel tank; 4\/5\/6 HP models share a common platform and may use an external tank on certain variants.\u003c\/li\u003e\n    \u003cli\u003eWhen ordering parts, match the exact model code and serial number to ensure correct gaskets, impeller kit, and carburetor‑related items.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"engine-overview\" style=\"padding:16px 0;\"\u003e\n  \u003ch2\u003ePlatform Overview\u003c\/h2\u003e\n\n  \u003ch3\u003eTohatsu MFS2.5 \/ MFS3.5 (4‑Stroke Portable)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%;max-width:1000px;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:8px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:8px;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eSingle‑cylinder, carbureted 4‑stroke, manual start, above‑prop exhaust; integral fuel tank with simple F‑N gear setup.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eMFS2.5, MFS3.5 (various shaft lengths and region codes)\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eVery light and portable; simple maintenance; ideal for dinghies and small inflatables.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eKeep the cooling system clear and service the water pump impeller on schedule. Verify plug type and gap and follow the manual’s oil spec (FC‑W 10W‑30 typical).\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003eTohatsu MFS4 \/ MFS5 \/ MFS6 (Shared Platform)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%;max-width:1000px;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:8px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:8px;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eSingle‑cylinder, carbureted 4‑stroke portable platform; many 4\/5\/6 HP parts interchange (impeller, gearcase seals, anodes).\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eMFS4, MFS5, MFS6 (S\/L shaft; options vary by market such as external fuel tank and charging options)\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eGood fuel economy, simple service, and broad parts availability across the shared platform.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eConfirm model\/serial for carburetor and jetting differences. Propeller pitch selection affects WOT rpm—verify with your hull\/load.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"service-kits\" style=\"padding:16px 0;\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp style=\"max-width:900px;\"\u003eIntervals below are general guidelines; always follow the official Tohatsu service manual for your exact model and operating conditions.\u003c\/p\u003e\n  \u003ctable style=\"width:100%;max-width:1100px;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:8px;\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:8px;\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:8px;\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:8px;\"\u003eParts Link\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eEngine oil (4‑Stroke)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eUse marine 4‑stroke oil (FC‑W 10W‑30 typical). Small portables generally do not use a spin‑on filter.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/tohatsu-outboard-parts\"\u003eTohatsu Outboard Parts\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eGear oil (lower unit)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eChange more often after heavy use or water intrusion checks. Use marine gear lube (SAE 80–90).\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/tohatsu-outboard-parts\"\u003eTohatsu Outboard Parts\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eSpark plug(s)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eInspect at 100 hours; replace as needed\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eCheck condition and gap; replace if fouled or worn.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/spark-plug\"\u003eSpark Plugs\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eFuel filter \/ in‑line filter\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eInspect at 100 hours; replace if contaminated\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eReplace sooner if stale fuel or debris is suspected.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-filters-1\"\u003eFuel Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eWater pump impeller \/ kit\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eEvery 2–3 seasons or ~200 hours\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eEssential for cooling; replace sooner if weak tell‑tale or overheating occurs.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/tohatsu-water-pump-repair-kits\"\u003eTohatsu Water Pump Repair Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eAnodes (gearcase\/trim tab, etc.)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eInspect every 50 hours; replace when ~50% depleted\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eDo not paint or grease. Critical for corrosion protection.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/anodes\"\u003eAnodes\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003ePropeller \u0026amp; shear pin\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eInspect regularly; after any strike\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eCheck for bent blades or damaged pin; verify pitch for proper WOT rpm.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/propellers\"\u003ePropellers\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eLower unit seals (as needed)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eIf water intrusion is found in gear oil\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eReseal before further operation to prevent gear damage.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/tohatsu-lower-unit-seal-kits\"\u003eTohatsu Lower Unit Seal Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n  \u003cp style=\"font-size:12px;color:#555;\"\u003e*Severe use (trolling, sandy\/silty water, heavy loads, high hours) may require shorter intervals.\u003c\/p\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"common-parts\" style=\"padding:16px 0;\"\u003e\n  \u003ch2\u003eFrequently Used Parts Categories\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eCooling System – \u003ca href=\"https:\/\/seasierra.com\/collections\/tohatsu-water-pump-repair-kits\"\u003eTohatsu Water Pump Repair Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eGearcase Service – \u003ca href=\"https:\/\/seasierra.com\/collections\/tohatsu-lower-unit-seal-kits\"\u003eTohatsu Lower Unit Seal Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCorrosion Protection – \u003ca href=\"https:\/\/seasierra.com\/collections\/anodes\"\u003eAnodes\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eFuel System – \u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-filters-1\"\u003eFuel Filters\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eIgnition – \u003ca href=\"https:\/\/seasierra.com\/collections\/spark-plug\"\u003eSpark Plugs\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003ePropulsion – \u003ca href=\"https:\/\/seasierra.com\/collections\/propellers\"\u003ePropellers\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eSealing \u0026amp; Repairs – \u003ca href=\"https:\/\/seasierra.com\/collections\/gaskets\"\u003eGaskets\u003c\/a\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"troubleshooting\" style=\"padding:16px 0;\"\u003e\n  \u003ch2\u003eCommon Symptoms \u0026amp; Quick Checks\u003c\/h2\u003e\n  \u003ctable style=\"width:100%;max-width:1100px;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:8px;\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:8px;\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:8px;\"\u003eRelated Parts\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eWeak tell‑tale or overheat alarm\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eVerify intake screen is clear; inspect impeller condition; ensure tell‑tale outlet isn’t clogged.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eWater pump impeller\/kit, intake screen, thermostat\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003ePoor acceleration \/ power loss\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eCheck propeller for damage; confirm fresh fuel; inspect\/replace fuel filter; check spark plug condition.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003ePropeller, fuel filter, spark plug\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eHard starting \/ rough idle\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eConfirm choke\/enrichment use on cold start; inspect plug gap; check for stale fuel and air leaks at fuel lines.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eSpark plug, fuel filter, fuel hose, carb service items\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eGearcase noise or milky gear oil\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eDrain and inspect gear oil for water; check for fishing line at prop shaft; reseal if water intrusion is found.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #eee;\"\u003eLower unit seal kit, gear oil, prop shaft seals\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"faq\" style=\"padding:16px 0;\"\u003e\n  \u003ch2\u003eFAQs\u003c\/h2\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eAre parts interchangeable between MFS4, MFS5, and MFS6?\u003c\/summary\u003e\n    \u003cp\u003eMany components are shared across the 4\/5\/6 HP platform (water pump kits, gearcase seals, anodes, some gaskets). Carburetor and jetting, prop pitch, and certain options can vary—confirm with your model code and serial number.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhen should I replace the water pump impeller?\u003c\/summary\u003e\n    \u003cp\u003eAs a preventive service, replace the impeller every 2–3 seasons (or ~200 hours). Replace immediately if you notice a weak tell‑tale stream, overheating, or after sand\/silt ingestion.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should I change lower unit gear oil?\u003c\/summary\u003e\n    \u003cp\u003eInspect and change at least annually or every 100 hours. If the oil appears milky or you find water intrusion, reseal the gearcase before further use.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat information do you need to confirm part compatibility?\u003c\/summary\u003e\n    \u003cp\u003ePlease provide: full model code (e.g., MFS2.5\/MFS3.5\/MFS4\/5\/6), serial number, shaft length (S\/L), and details on options (external tank, charging). A photo of the nameplate and the part to replace is very helpful.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"cta\" style=\"padding:16px 0;\"\u003e\n  \u003cp\u003eReady to find parts for your Tohatsu 2.5–6 HP 4‑Stroke? Browse the main collection by horsepower, year, and model.\u003c\/p\u003e\n  \u003ca href=\"https:\/\/seasierra.com\/collections\/tohatsu-outboard-parts\" style=\"display:inline-block;margin-top:6px;padding:10px 14px;border-radius:6px;background:#0b6efd;color:#fff;text-decoration:none;\"\u003eShop Tohatsu Outboard Parts\u003c\/a\u003e\n  \u003cp style=\"margin-top:8px;color:#555;\"\u003eIf you’re unsure about your model, send us a photo of the nameplate and the part you need and we’ll help verify compatibility.\u003c\/p\u003e\n\u003c\/section\u003e","products":[{"product_id":"water-pump-impeller-fits-mercury-tohatsu-evinrude-2-5-6-hp-4-stroke-2-5-hp-2-stroke-replaces-47-161543-369-65021-1-5040180","title":"Aftermarket Water Pump Impeller for Nissan\/Tohatsu 2–6 HP Outboards and Mercury 2–3.5 HP 4-Stroke Models","description":"\u003csection\u003e\n\u003cstyle\u003e\n  .ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\n  table.ss-table { width:100%; border-collapse:collapse; min-width:640px; }\n  table.ss-table th, table.ss-table td {\n    padding:10px 12px; border:1px solid #e5e7eb; text-align:left; vertical-align:top;\n  }\n  table.ss-table th {\n    white-space:nowrap;\n    word-break:normal;\n    letter-spacing:normal;\n    font-weight:600;\n    background:#f8fafc;\n  }\n  @media (max-width:480px){\n    table.ss-table th, table.ss-table td { padding:8px 10px; font-size:14px; }\n  }\n\u003c\/style\u003e\n\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis aftermarket \u003cstrong\u003ewater pump impeller\u003c\/strong\u003e is designed for selected small Nissan\/Tohatsu and Mercury\/Mariner outboard applications. It supports Nissan 3.5B\/NS5B engines, Tohatsu 2-stroke 2 HP, 2.5 HP, 2.5A, 3.5A, 3.5B, 3.5 HP, 4 HP, and 5 HP models, as well as Tohatsu 4-stroke MFS4, MFS5, and MFS6 HP models. The company fitment information also identifies Mercury\/Mariner 4-stroke 2 HP, 2.5 HP, and 3.5 HP carbureted applications.\u003c\/p\u003e\n\u003cp\u003eThe impeller is a direct replacement component for water pump service when its dimensions and original part reference match your engine. Catalog records also associate the primary Tohatsu reference with selected M2\/M2.5\/M3.5, M4\/M5, MFS2\/MFS2.5\/MFS3.5, and MFS4\/MFS5\/MFS6 engine applications. Always confirm the exact model and service information before installation.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSingle aftermarket water pump impeller.\u003c\/li\u003e\n  \u003cli\u003eSix-blade design for the listed outboard applications.\u003c\/li\u003e\n  \u003cli\u003eInside diameter: 10.25 mm.\u003c\/li\u003e\n  \u003cli\u003eOutside diameter: 33.6 mm.\u003c\/li\u003e\n  \u003cli\u003eWidth: 14.2 mm.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eThe following OEM and aftermarket references are associated with this impeller. A reference number alone does not replace confirmation of the complete engine model and application.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Part Number Interchange\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n\u003cth\u003eBrand or Supplier\u003c\/th\u003e\n\u003cth\u003eReference Number\u003c\/th\u003e\n\u003cth\u003eReference Type\u003c\/th\u003e\n\u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003ctd\u003eTohatsu\u003c\/td\u003e\n\u003ctd\u003e369-65021-1\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eTohatsu\u003c\/td\u003e\n\u003ctd\u003e369650211M\u003c\/td\u003e\n\u003ctd\u003eOEM reference format\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury Marine\u003c\/td\u003e\n\u003ctd\u003e47-16154-3\u003c\/td\u003e\n\u003ctd\u003eOEM reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury Marine\u003c\/td\u003e\n\u003ctd\u003e47-161543\u003c\/td\u003e\n\u003ctd\u003eOEM reference format\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury Marine\u003c\/td\u003e\n\u003ctd\u003e8M0204676\u003c\/td\u003e\n\u003ctd\u003eReference number\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eEvinrude \/ Johnson \/ OMC \/ BRP\u003c\/td\u003e\n\u003ctd\u003e5040180\u003c\/td\u003e\n\u003ctd\u003eReference number\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-3098\u003c\/td\u003e\n\u003ctd\u003eAftermarket reference\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMallory\u003c\/td\u003e\n\u003ctd\u003e9-45302\u003c\/td\u003e\n\u003ctd\u003eAftermarket reference\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eEngine \u0026amp; Model Compatibility\u003c\/h2\u003e\n\u003cp\u003eFitment is application-specific. Keep the horsepower, stroke, model family, and any carburetor or serial-number conditions together when checking your engine. The table below summarizes the applications explicitly identified for this product and related catalog records.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine Compatibility\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003eModel or Application\u003c\/th\u003e\n        \u003cth\u003eRated HP\u003c\/th\u003e\n        \u003cth\u003eStroke\u003c\/th\u003e\n        \u003cth\u003eApplication Notes\u003c\/th\u003e\n        \u003cth\u003eReference\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003ctd\u003eNissan\u003c\/td\u003e\n\u003ctd\u003e3.5B \/ NS5B\u003c\/td\u003e\n\u003ctd\u003e3.5–5\u003c\/td\u003e\n\u003ctd\u003eNot stated in company record\u003c\/td\u003e\n\u003ctd\u003eConfirm exact model designation\u003c\/td\u003e\n\u003ctd\u003e369-65021-1\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eTohatsu\u003c\/td\u003e\n\u003ctd\u003e2 HP\u003c\/td\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003eCompany-listed application\u003c\/td\u003e\n\u003ctd\u003e369-65021-1\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eTohatsu\u003c\/td\u003e\n\u003ctd\u003e2.5 HP; 2.5A; 3.5A; 3.5B\u003c\/td\u003e\n\u003ctd\u003e2.5–3.5\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003eCompany-listed application\u003c\/td\u003e\n\u003ctd\u003e369-65021-1\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eTohatsu\u003c\/td\u003e\n\u003ctd\u003e3.5 HP\u003c\/td\u003e\n\u003ctd\u003e3.5\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003eCompany-listed application\u003c\/td\u003e\n\u003ctd\u003e369-65021-1\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eTohatsu\u003c\/td\u003e\n\u003ctd\u003e4 HP \/ 5 HP\u003c\/td\u003e\n\u003ctd\u003e4–5\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003eCompany-listed application\u003c\/td\u003e\n\u003ctd\u003e369-65021-1\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eTohatsu\u003c\/td\u003e\n\u003ctd\u003eMFS4 \/ MFS5 \/ MFS6\u003c\/td\u003e\n\u003ctd\u003e4–6\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003eCompany-listed application\u003c\/td\u003e\n\u003ctd\u003e369-65021-1\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury \/ Mariner\u003c\/td\u003e\n\u003ctd\u003e4-stroke 2 HP, 2.5 HP, and 3.5 HP carbureted models\u003c\/td\u003e\n\u003ctd\u003e2–3.5\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003eConfirm carburetor version and exact model\u003c\/td\u003e\n\u003ctd\u003e47-16154-3\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specs\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n  \u003cdd\u003eWater Pump Impeller\u003c\/dd\u003e\n  \u003cdt\u003eProduct Construction\u003c\/dt\u003e\n  \u003cdd\u003eRubber impeller\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n  \u003cdd\u003eReplacement water pump component\u003c\/dd\u003e\n  \u003cdt\u003eInside Diameter\u003c\/dt\u003e\n  \u003cdd\u003e10.25 mm\u003c\/dd\u003e\n  \u003cdt\u003eOutside Diameter\u003c\/dt\u003e\n  \u003cdd\u003e33.6 mm\u003c\/dd\u003e\n  \u003cdt\u003eWidth\u003c\/dt\u003e\n  \u003cdd\u003e14.2 mm\u003c\/dd\u003e\n  \u003cdt\u003eBlade Configuration\u003c\/dt\u003e\n  \u003cdd\u003e6 blades\u003c\/dd\u003e\n  \u003cdt\u003eQuantity\u003c\/dt\u003e\n  \u003cdd\u003e1 impeller\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e1 x aftermarket water pump impeller\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eConfirm the engine model, stroke, application details, and original impeller reference before starting work.\u003c\/li\u003e\n  \u003cli\u003eFollow the outboard manufacturer's service procedure for removing the lower unit and water pump housing.\u003c\/li\u003e\n  \u003cli\u003eRemove the old impeller and inspect the housing, wear plate, key, water tube, and related pump components for damage or corrosion.\u003c\/li\u003e\n  \u003cli\u003eClean debris and corrosion from the pump area before installing the replacement impeller.\u003c\/li\u003e\n  \u003cli\u003eInstall the impeller in the same orientation specified by the service manual. Use only an installation lubricant approved for the application.\u003c\/li\u003e\n  \u003cli\u003eReassemble the water pump and lower unit using the manufacturer's tightening sequence and torque specifications.\u003c\/li\u003e\n  \u003cli\u003eRun the engine only in an appropriate water supply or service tank and verify a strong cooling-water discharge before normal operation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow do I confirm that this impeller fits my engine?\u003c\/summary\u003e\n  \u003cp\u003eCompare your original impeller's reference number and dimensions, then check the complete engine model, horsepower, stroke, and application details against the compatibility information above. For Mercury\/Mariner models, confirm the 4-stroke 2 HP, 2.5 HP, or 3.5 HP carbureted application. If the model or part details differ, consult the engine service manual before ordering.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are common signs of a worn water pump impeller?\u003c\/summary\u003e\n  \u003cp\u003eA weak or missing tell-tale stream, overheating, or visible cracked, brittle, distorted, or missing blades can indicate that the impeller or another cooling-system component requires service.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this an OEM part?\u003c\/summary\u003e\n  \u003cp\u003eThis is an aftermarket replacement impeller. The OEM and aftermarket numbers shown above are reference numbers used to help identify applications; the product is not represented as a genuine OEM component.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eDoes the package include a key, gasket, or water pump housing?\u003c\/summary\u003e\n  \u003cp\u003eNo. The package contains one water pump impeller only. A key, gasket, housing, wear plate, or complete water pump kit is not included unless separately stated in the order details.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow often should the impeller be replaced?\u003c\/summary\u003e\n  \u003cp\u003eReplacement timing depends on the engine manufacturer's maintenance schedule and operating conditions. Inspect the impeller during scheduled water pump service and replace it if the blades show wear, cracking, distortion, or damage.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Information\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eVerify the original part number, dimensions, engine model, horsepower, and stroke before purchase.\u003c\/li\u003e\n  \u003cli\u003eDo not rely on horsepower alone to determine fitment; model family and application details can change the required impeller.\u003c\/li\u003e\n  \u003cli\u003eUse the manufacturer's service manual for lower-unit removal, installation orientation, torque specifications, and testing procedures.\u003c\/li\u003e\n  \u003cli\u003eThis is an aftermarket replacement component and is not a genuine OEM part.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation by a qualified marine technician is recommended when the required service procedure is unfamiliar.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMarine Replacement Parts\u003c\/strong\u003e — We provide aftermarket components for routine outboard maintenance and repair.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApplication-Focused Information\u003c\/strong\u003e — Product references and fitment details are presented to help customers compare their original part and engine specifications.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePractical Service Support\u003c\/strong\u003e — Follow the engine manufacturer's service instructions for safe installation and reliable operation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723801530683,"sku":"17IT001","price":14.08,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/17IT0011_0dc8836f-1498-48cd-bd0b-0cdc8bf62f2c.jpg?v=1763032196"}],"url":"https:\/\/seasierra.com\/collections\/tohatsu-2-5-6-hp-4-stroke-outboard-marine-engine-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}